Patterned layers of silicon-containing oxide, for example silicon dioxide, may be used for various purposes. Notably in semiconductor technology, in particular planar semiconductor technology, such patterned layers of silicon-containing oxide are used as diffusion masks, as passivating layers, and/or as dielectric layers, such as in MOS-structures. In general, first the oxide layer is formed, after which the desired pattern is etched therein using a photoresist layer developed in the desired pattern on the oxide layer and a suitable etchant. The photoresist may be a polymerizable material which has been made sensitive to ultraviolet radiation by suitable additions.
However, in this known method defects and inaccuracies may occur which may be the result of undesired pores in the developed photoresist layer as a result of which the oxide layer is etched away at undesired places, and/or may be caused by underetching as a result of which inaccuracies in the dimensions of the apertures to be obtained in the patterned oxide layer may occur and the pits etched below the undesired pores may become unacceptably large.
It has already been proposed to obtain a more accurate definition of the resist layer by the use of particle radiation, for example electron beams, with which theoretically a better definition should be obtainable. However, this requires expensive equipment. Furthermore, the said possible defects as a result of pores and underetching are not avoided.
It has meanwhile been found that it is possible to influence siloxane-containing layers by means of local electron bombardment in such a manner that a difference in properties is formed between siloxane material thus bombarded and unbombarded siloxane material, it being possible to remove one of the said two materials while leaving the other material on a substrate. The resulting pattern of the siloxane-containing material may then be converted into silicon-containing oxide by heating in an oxygen-containing atmosphere, for example air. As no etching step is used, underetching cannot occur. Pores, if any, are small and may be closed during the conversion into the oxide or during a possible further after-treatment.
However, the drawback of the use of expensive equipment remains.
It has now been found possible to form a silicon-containing layer which is sensitive to ultraviolet radiation and which can be provided on a substrate in a given pattern using such radiation and a suitable mask, which pattern can be converted into a corresponding pattern of silicon-containing oxide.